Preparation and properties of C₆₀-containing poly(vinyl alcohol)

Poly(vinyl alcohol) (PVA) was reacted with strong base NaH to yield pendant oxy anions, followed with nucleophilic addition to C₆₀. The resulted PVA(C₆₀-Na⁺)_n products were then converted to PVA(C₆₀H)_n by stirring with a strong acid cation exchanger of H⁺-form. Extraction of the C₆₀-containing PVAs by toluene, which is a good solvent for C₆₀, exhibits no color transfer to the toluene phase. The C₆₀-containing PVAs were identified by the characteristic IR and UV-Vis absorptions of C₆₀. The electrochemical behaviors in solution or in film state were investigated by cyclic voltammetric methods. The cyclic voltammogram of 4a shows a reduction peak at -2.30 V which should be due to the bonded C₆₀ chromophores. In the film state, obtained by coating C₆₀-containing PVA solution on graphite electrode, PVA(C₆₀-Na⁺)_n is much easily reduced and oxidized than PVA(C₆₀H)_n. Furthermore, the difference in this reduction and oxidation feasibility is enhanced with increasing C₆₀ content. However, coating with PVA(C₆₀H)_n or PVA(C₆₀-Na⁺)_n reduces the redox ability of the graphite electrode.